A complete model of keyhole and melt pool dynamics to analyze instabilities and collapse during laser welding

Mickael Courtois (1, 2) , Muriel Carin (1) , Philippe Le Masson (1) , Sadok Gaied (2) , Mikhaël Balabane (3)

1 LIMATB - Laboratoire d'Ingénierie des Matériaux de Bretagne
2 ArcelorMittal Montataire Research - Automotive Applications
3 LAGA - Laboratoire Analyse, Géométrie et Applications

A complete modeling of heat and fluid flow applied to laser welding regimes is proposed. This model has been developed using only a graphical user interface of a finite element commercial code and can be easily usable in industrial R&D environments. The model takes into account the three phases of the matter: the vaporized metal, the liquid phase, and the solid base. The liquid/vapor interface is tracked using the Level-Set method. To model the energy deposition, a new approach is proposed which consists of treating laser under its wave form by solving Maxwell's equations. All these physics are coupled and solved simultaneously in Comsol Multyphysics®. The simulations show keyhole oscillations and the formation of porosity. A comparison of melt pool shapes evolution calculated from the simulations and experimental macrographs shows good correlation. Finally, the results of a three-dimensional simulation of a laser welding process are presented. The well-known phenomenon of humping is clearly shown by the model.

Mots clés: level set; melt pool; fluid flow modeling; porosities; keyhole; laser welding

Domaines: Génie mécanique [physics.class-ph]

Mickael Courtois, Muriel Carin, Philippe Le Masson, Sadok Gaied, Mikhaël Balabane. A complete model of keyhole and melt pool dynamics to analyze instabilities and collapse during laser welding. Journal of Laser Applications, 2014, 26 (4), pp.042001. ⟨10.2351/1.4886835⟩. ⟨hal-01113130⟩